Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Successful filming of fastest aurora flickering


The word "aurora" invokes an image of a slowly shimmering curtain of light illuminating the sky. However, when an explosive aurora occurs, known as a breakup, it sometimes leads to another phenomenon called "flickering". When an aurora "flickers" its brightness and motion in some areas begin to change rapidly. This flickering typically oscillates at a 1/10 second period, which is equivalent to the ion cyclotron frequency (*1) of oxygen ions.

Dr. Yoko Fukuda (formally of the Graduate School of Science at The University of Tokyo), Dr. Ryuho Kataoka of the National Institute of Polar Research, and other collaborators conducted a 3 year continuous high-speed imaging observation at Poker Flat Research Range, Alaska, USA, and identified the physics behind the flickering. At the same time, they discovered faster flickerings at speeds of 1/60-1/50 and 1/80 of a second.

This is a flickering aurora. The pale pink area at the center is flickering. Filmed by: Ayumi Y. Bakken, filmed at: Fairbanks, AK, USA; filming date: March 18, 2015; playback speed: 1x.

Credit: Ayumi Y. Bakken

These are high-speed cameras installed at the Neal Davis Science Operations Center at the Poker Flat Research Range of the University of Alaska.

Credit: NIPR

On March 19, 2016, the researchers observed an aurora with the brightness that ranked within the top 5 of all observations since 2014, and was filmed with a 1/160 second shutter speed camera. Detailed analysis of the footage showed a high-speed flickering aurora vibrating with a 1/80 second period taking place during the brightest moment of the breakup.

"High-speed flickering at 1/80 seconds could not be explained by oxygen ions alone. Lighter ions, such as those from hydrogen, are thought to be contributing to the flickering," explains Dr. Fukuda. "The fact that this high-speed flickering was observed at the same time as flickering with a typical 1/10 second period may mean that the flickering aurora was caused by 'electromagnetic ion cyclotron waves' (*2), which are affected by both oxygen and hydrogen ions."

At altitudes of several thousand kilometers, various plasma waves are excited by accelerating electrons and ions. These electrons are what eventually generate auroras. It is assumed that a complex exchange of energy, in which plasma waves are affected by electrons and ions and vice versa, takes place here.

"Astronomical objects with magnetic fields are found throughout the cosmos, with Earth being one of them. On such objects, we observe excitation of plasma waves by accelerating particles, and the interactions between plasma waves and particles, are occurring all over the place," concludes Dr. Kataoka. "However, Earth is the only place we can observe these phenomena in detail. Understanding the behavior of plasma in outer space, and the interactions between plasma waves and particles is a fundamental question in geophysics. We will continue to investigate them in the future."


*1: Ion cyclotron frequency

The circular motion of electrons and ions around a magnetic field line is called cyclotron motion. Ion cyclotron frequency is the number of times per second that the electrons and ions circle around the field line. It is inversely proportional to the mass of the electrons and ions--the frequency is greater if the mass is lighter. The frequency also correlates with the strength of the magnetic field; it is greater at lower altitudes where the magnetic field is stronger.

*2: Electromagnetic ion cyclotron waves

A type of wave that can exist in a plasma (such as the region of space above Earth's aurora), which vibrates at an ion cyclotron frequency that corresponds to the ion type present (oxygen, helium, hydrogen, etc.).

This is a joint press release by National Institute of Polar Research(NIPR), The University of Tokyo, Nagoya University, Kyoto University, University of Alaska, Fairbanks and University of Southampton.

Media Contact

Public Relations Section, NIPR

Public Relations Section, NIPR | EurekAlert!

Further reports about: Electrons cyclotron cyclotron frequency ions magnetic field waves

More articles from Earth Sciences:

nachricht New technologies and computing power to help strengthen population data
22.03.2018 | University of Southampton

nachricht New interactive map shows climate change everywhere in world
22.03.2018 | University of Cincinnati

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Modular safety concept increases flexibility in plant conversion

22.03.2018 | Trade Fair News

New interactive map shows climate change everywhere in world

22.03.2018 | Earth Sciences

New technologies and computing power to help strengthen population data

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>